I wouldn't say that your MAF can no longer adapt to the increased air thus maxing out. It seems like your MAF is slow to respond.
Yeah, 3.76 gears are going to make a difference off the line. You might want to consider your daily driven vehicle is going to see freeway useage.
Yes, I've owned 3 Lexus' in the past. I have 2.93 gears and I can hang with you. :D